Prior expectation enhances sensorimotor behavior by modulating population tuning and subspace activity in the sensory cortex

Abstract

Prior knowledge facilitates our perception and goal-directed behaviors in the dynamic world, particularly when sensory input is lacking or noisy. However, the neural mechanisms underlying how prior expectation improves sensory-motor behaviors remain unknown. Herein, we examined neural activity in the middle temporal visual area (MT) while monkeys perform a smooth pursuit eye movement task with the prior expectation of the visual target's motion direction. We found that prior expectation discriminately reduced the MT neural responses depending on their preferred directions, only when the sensory evidence was weak. This response reduction effectively sharpens neural population direction tuning. Furthermore, the state-space analysis showed the task-specific prior expectation signals in population activity. In-silico simulations with a realistic MT population demonstrated that the sharpening of the tuning fully explained the biases and variabilities in smooth pursuit, suggesting neural computations in the sensory area alone can underpin the integration of prior knowledge and sensory evidence.

Brain-wide representations of prior information in mouse decision-making

“…Such a model would predict that prior information should be available throughout the brain, even in low level cortical sensory areas (Berkes et al, 2011;Bondy et al, 2018;Kok et al, 2012;Lange & Haefner, 2022). The current literature offers a contradictory, and thus inconclusive, perspective on whether the prior is indeed encoded in brain regions associated with early processing (Bell et al, 2016;Bondy et al, 2018;Haefner et al, 2016;Han & Helmchen, 2023;Hanks et al, 2011;Ishizu et al, 2023;Mayrhofer et al, 2019;Park et al, 2022;Platt & Glimcher, 1999;Rao et al, 2012;Son et al, 2023). This is because past studies have collectively recorded from only a limited set of areas; and, since they use different tasks, even these results cannot be fully integrated.…”

Localized and global representation of prior value, sensory evidence, and choice in male mouse cerebral cortex

“…Our study appreciated the Neuropixels probe and found that the prior-value representations were distributed across cortical areas. As the prior knowledge about the task is essential not only for executing action at the late stage of decision processing but also for modulating sensory processing 55 or for 8 | State space analysis explains orthogonalized separations of block and sound in the auditory cortex (AC) and stable block separations in the AC, secondary motor cortex (M2), and medial prefrontal cortex (mPFC). a Schematic of state-dynamics analysis.…”

Localized and global representation of prior value, sensory evidence, and choice in male mouse cerebral cortex

“…Our study appreciated the Neuropixels probe and found that the prior-value representations were distributed across cortical areas. As the prior knowledge about the task is essential not only for executing action at the late stage of decision processing but also for modulating sensory processing 55 or for predictive coding based on prediction errors [56][57][58] , the global prior representations are possibly important for various steps of decision making.…”